Abstract

Quaternary III-VInAsSbPquantum dots(QDs) have been grown in the form of cooperative InAsSb/InAsP structures using a modified version of the liquid phase epitaxy. High resolution scanning electron microscopy, atomic force microscopy, and Fourier-transform infrared spectrometry were used to investigate these so-called nano-camomiles, mainly consisting of a central InAsSbQD surrounded by six InAsP-QDs, that shall be referred to as leaves in the following. The observed QDs average density ranges from 0.8 to 2 , with heights and widths dimensions from 2 to 20 nm and 5 to 45 nm, respectively. The average density of the leaves is equal to (6-10) with dimensions of approx. 5 to 40 nm in width and depth. To achieve a first basic understanding of the electronic properties, we have modeled these novel nanostructures using second-order continuum elasticity theory and an eight-band model to calculate the electronic structure. Our calculations found a clear localization of hole states in the central InAsSb dot. The localization of electron states, however, was found to be weak and might thus be easily influenced by external electric fields or strain.

Received 19 April 2011Accepted 01 July 2011Published online 22 August 2011

Acknowledgments:

The authors wish to thank Prof. Dr. R. Fornari, Dr. T. Boeck from Leibniz Institute for Crystal Growth (IKZ, Berlin), and Ms. M. Schulze (now at Bosch AG) for SEM and AFM measurements. Parts of this work have been carried out in the frames of the Armenian National Governmental Program for Nano-Electronics and of the ISTC grant A-1232.